Inverse Mass
by Luc Court
Summary: PreCoM, spoilers for KH2. Xaldincentric. Some members of the Organization escape their pasts. Others find it interwoven with their present, no matter how much seems to change.


**Inverse Mass  
**_Spoilers for KH2. Pre-CoM. Xaldin and Xemnas. Related to Magpies, I guess._

The World that Never Was is a brilliant spark among the Darkness. Or Nothingness; Xaldin can't always tell the two apart, not with how Zexion and Vexen like to argue back and forth as if words are flexible as willow-trees, as if it doesn't matter what they're saying because none of it makes sense in the end. Nothingness. Darkness. Light. Dusks. Shadows.

But even if the theory is inconsistent, the World is not. The Castle is a beacon that draws him back home no matter how far he has strayed. He leaves the strange half-paths of Oblivion behind him willingly, abandoning Marluxia's feline smugness and Lexaeus's assurances and the strange look on Namine's face when they told her she would be staying there from now on.

His feet barely make any noise when they touch down.

A contingent of Dragoons is already waiting. He's inwardly proud of this; his Dusks are among the most disciplined, even for creatures which follow commands to the utmost obedience. They assemble in rank on the upper platform of the Castle where he keeps his quarters, already prepared for any order, no matter how small.

But mixed among their white, intricate bodies, there is a dark shape - a figure which has no reason to be visiting the Dusks, which should have a separate rank of creatures to attend to.

It turns, and Xaldin feels a jab of recognition before the man even takes down his hood.

"Xemnas." It is not common for the Superior to come visiting; normally Xemnas chooses to debate with Vexen or Zexion, calling on other members rarely for consultation. Since both his traditional partners have departed to attend Namine, Xaldin can only assume this leaves the Superior with few conversational options. "What are you doing here?"

The other man smiles. The expression is thin; Xemnas doesn't seem to know how to form his lips properly around the shape anymore, because half the time, there's not even falsified emotion. He steps away from the Dragoons readily. "We haven't had a chance to speak much lately, not since the construction of Castle Oblivion began." A pause. "It's... been a while since I saw you wearing goggles."

Self-consciously, Xaldin touches his temple; he'd forgotten to take the lenses off in transit. At the reminder, he shoves them up anyway, until they're nestled just above his scalp-line. "I was checking on some of the stairways in Oblivion. I thought it best if I surveyed how the foundation was being laid - directly, not just from reports."

Xemnas's voice holds only a hint of reproach. "It _is_ self-creating."

"Caution never hurts when it comes to these things."

Xemnas gives him a quick, fragile smile. "I suppose old habits never die." Another step, and the man continues to prowl away from the Dusks, pacing sidelong so that there is a wide sweep of empty space between himself and their master. "Since I'm visiting anyway - shall we duel?"

* * *

Dilan's mother was a sturdy woman. He took his height from her. There had been something violent about his birth - early labor, he'd been turned the wrong way, she'd been on the work crews until the very moment her muscles clenched - and she'd never had a second child follow.

"So eager to start working that you _had_ to come out right away," his mother liked to tease, patting him on the arm with the horrible, humiliating affection of a parent who didn't realize their child wasn't toddling anymore.

Of his father, she spoke little. Dilan had gathered that the man had spent a brief time with her before they had mutually parted ways; he was another engineer in the King's service, gone to build bridges in the western towns, a footnote in the annuals of construction.

Dilan's mother had not feared single parenthood. On the contrary, she seemed to consider her son as just another project, to dabble and mold and raise as deftly as the half-dozen other structural models lingering around their cluttered home. They shared the same blue eyes; a dozen pictures were hung around the kitchen featuring the two of them together, Dilan being pulled into the shot while his mother pushed up her goggles, and grinned.

She was always shameless, even while quarreling with her fellow engineers, challenging the King himself as she laid out the groundwork for another project. Dilan had been on the receiving end of her enthusiasm more than once. Unluckily enough, Braig also shared her temperament; the two of them were lethal when put in the same room together, and it always seemed as if Dilan was nursing a fresh bruise after their mad mutual inspiration calmed down.

"These cinch-locks will keep your hair from getting caught in the gears again," she had consoled him one day, perched on the sink rim like an overenthusiastic chipmunk.

"Mother," Dilan groaned. The kitchen simmered with various oils, food mixing with mechanical, laced with the crisp tang of bottled lightning cells. "Can't I just wear it loose?"

"Unless you want the rest of your scalp ripped off in a half a year, no," she clucked. Strong fingers grabbed another clump of hair, yanking the strands as she bunched them together in a line and then slathered waxy gel across. "It's that or shave, and you refuse that option."

"_Braig_ doesn't wear his hair in a braid."

"_Braig_ - bless his scrawny, fish-salt heart - isn't a castle tech." Another tug, and then the woman was tsking over the raw red scrapes that had been left behind when Dilan's ponytail had been trapped in the cogs of his last class project. Braig had been convinced that they'd had to aim big; an automated star chart was a good idea on paper, but messy in execution. "And you're not one either, but I won't let any son of mine look like a greenclad novice."

She shooed him back to class when the weekend was over, shoving wax and bandages and extra burn cream at him, just in case. "Don't forget your goggles this time, Dilan."

"I have them, Mother."

"And your toolkit, I know how you had to borrow off the work crews last time, don't think I didn't hear about it."

"I know, Mother."

"And don't forget to stop by and see me downstairs, just because you're playing sports after class doesn't mean you have to be a stranger."

"I _know!_"

* * *

"Is it true that you're the best at magic?"

The new student's face was as fresh as a spring lotus: smooth of any freckles or scars. It was lightly tanned, but not sunbeaten. Dilan, judging the color, had assumed Xehanort had come from out of town before later discovering the truth.

"Did Even tell you that?" The thought birthed a laugh out of Dilan's throat, but one lacking amusement. "I'm not. I just dealt with it a lot as a kid - nothing flashy, just the practical stuff. Even can't make a distinction between the two. Things are, or they aren't. It's science, or it's nothing." Another dry cough, humorless, and then Dilan focused on the boy standing in front of him. "Are you asking me this because of the test we had this morning?"

Xehanort nodded.

Ansem the Wise had called out his students onto the front lawns that day, pointing to an ornate cage of metal bars and a tiny white ball in one corner. The challenge involved getting the sphere from the starting point all the way through the inner maze to the far side, without allowing the ball to contact any of the bars. A relatively straightforward test, compared to their more intricate exams; this one measured magical control alone, with an emphasis on precision and visualization.

Braig was the fastest, accomplishing the goal in under five seconds - and was promptly marked down for cheating with Gravity magics, using them to teleport the ball from one side to the other instead of guiding it through.

After him, Dilan had won first place, marking twenty-point-three seconds down for the accomplishment. Then, because he was bored, he levitated the gridwork itself and moved it around the stationary orb, rotating the shape easily as he returned the sphere to the start. This feat earned him a hateful look from Even's direction; the younger student did not have enough staying power to even make it halfway through the test, and had to accept a partial mark.

For Dilan, it was effortless. His mother had trained him with similar exercises from the cradle, begging him to pass over a wrench from across the room, or gather carpenter's nails off the floor. She herself could suspend an entire stripped mechanism in her hands, floating parts dismembered for reassembly while she examined each in turn, air currents deftly holding everything in place. _Better than gravity_, she would twitter, _less pressure on the components and easier to manage._

Dilan used the same trick in school to juggle pencils when he was bored.

"It's because I see the intangible." Breaking his own silence, Dilan shrugged. "Magic gets easier when you know how to manipulate what isn't visible."

Xehanort had absorbed the statement solemnly, giving an enthusiastic nod before he proceeded with his next misinformed question. "So, what are you? Are you here for research labs with the rest of us? Or are you a castle engineer?"

"I'm a student." The answer was suddenly tiresome. Absolute definitions held no room for dabblers, but Dilan had picked up lessons from everything. "That's all."

* * *

They begin the fight gingerly, two creatures testing the limits of the other's power without intention of true harm. The Dusks shuffle to the corners of the balcony. Xaldin prefers to practice under open skies; even a cathedral like Saix's room isn't big enough for Xaldin's tastes. Not enough air currents to manipulate safely.

Xemnas makes the first advance, darting forward across the empty platform like a cat outstretching, both hands bare of weapons. Xaldin's parry is effortless; he sweeps his lances in front of him without a second thought. Too late, he realizes the mistake in utilizing a static defense - but Xemnas has already summoned his twin blades, slashing a path clear for the man to continue his charge.

Three lances dart back to Xaldin's side. He crosses them in a mobile weave even as he backpedals, short hops of motion as he resists the temptation to slip through Darkness to better reposition. Xemnas is not a sophisticated fighter. He was never tutored in the Bastion, and the lack shows in his footwork, in his body; Xaldin reads the motions effortlessly, dodging each wild slash up until he gets an elbow in the stomach.

The impact is surprising. He hadn't expected Xemnas to remain aware of the glitter of his weapons; far too easy to fall into the trap of watching the red swords instead of the arms wielding them. Six lances scatter as Xaldin stumbles back - he lashes out with a snap-kick in retort, and hears the other man grunt as both of them crash down.

Fighting with magic for so long has dulled his skills. It cripples Xemnas in a polite spar; both of them use only the bare minimum required to channel their weapons, and Xaldin has had years of practice before becoming a Nobody. They both roll away from each other, blindly recovering distance. It takes only a thought to sweep the lances into the air again, and as he scrabbles upright, Xaldin grabs for the blur in front of his eyes.

Unluckily, this is one of Xemnas's swords.

Part of him expects to be burned on contact, but the weight feels like - holding nothing, really, this inverse mass that can destroy anything it doesn't agree with. It's a manifestation which reminds him eerily of Xemnas himself; he is holding the soul of the Superior in his hands, and it has not killed him yet because he is being exceedingly careful about how little he touches.

The lances splay in a shield-wall defense. Xemnas skids to a halt; he's moving too fast, and the aborted run turns into a slide that takes him low under the deadly blades. Having no other inspiration, Xaldin flings the man's sword back at him, diving for his own weapons; they pass one another without comment, parallel counterweights in black.

Xaldin's body breaks harmlessly through the spinning lances. They crest around him like clouds. He lands on his hands, and the motion cartwheels him back to his feet.

Cheating comes halfway through, as predicted. It's fuzzy who starts first, who breaks the laws, because all too soon, Xaldin finds himself running pelt-melt down the side of the Castle, ignoring gravity as he works in free-fall.

Xemnas is already there, dodging around a crenellation. His coat blots out triangle chunks of stars. Xaldin is quick enough that he manages to plant a boot right in the Superior's ribs, a nasty kick that sends the man crashing through a window - or would, if Xemnas didn't slide straight through Darkness instead, flickering out of material existence and reemerging at a different velocity out the wall. He catches himself by twisting off a rampart, spinning around so that he's falling _up_ now, up into empty space, and Xaldin has no other option than to follow.

Power sparks in electrical waves as they fence. It's a storm waged by gods. They both open portal after portal, disappearing in slices of time as they second-guess where the other has gone. Xemnas's swords leave red streams in the air, afterglows of energy; Xaldin's lances scream like a rabid pinwheel, spinning around his body in synchronized time.

They fight like dancers. They fight like jilted lovers, bitter about fates neither can deny; primal elements, forces of nature, doomed souls.

And all Xaldin can think is how brilliant they must look: how strong, how vibrant, how alive.

* * *

It was unusually hot the summer that his mother died.

Dilan's skin stuck to the back of the classroom chairs. Braig groaned and complained whenever he had the energy, and even Ienzo's face looked flushed and bronze from the heat.

Even took the temperatures most poorly out of all of them, selfishly keeping his frost magics to himself under the claim that he would melt otherwise.

That was the summer that a new bridge was being constructed on the eastern side of the Castle, across the Rising Falls. Dilan's mother was supervising the project. It had been half a year in planning, with no new designs to implement; the bridge was standard fare, with nothing to complicate matters.

Complacency might have been at fault. Or the heat, making people careless and sleepy. During the mid-afternoon processing of several tons of flagstone, one suspension load had been misaligned when it had been sent out, and had promptly tipped over.

Safety nets sprung to life. Energy laced in a protective net wove out underneath the bridge, effortlessly catching the pounds of rock that were sliding dangerously close to the floating engineer crews that were surveying the underbelly of the bridge.

The workers exhaled in relief; a few of them joked as they began to call for ladders to recover the slip.

And then the safeties had broken.

First row, second row, all flashing green and red as their weight-bearing capacities were strained; then something went wrong, a formula in the magics had been mislaid, and the third net snapped. Ropes groaned. Suspension fields crumpled, pouring marble blocks down upon the workers underneath; then their rigging had snapped as well, leaving them to fall helplessly in a tumble of flesh and stone.

They were still recovering bodies from the rubble. Some of the deaths had been identified.

Dilan's mother had been one of the first.

He didn't go home for a week.

Braig was generous enough when Dilan knocked on his door, stepping aside to let the other student pass. The two of them had forged a friendship early on, rooted in labwork: Braig and Dilan specialized in physical sciences, while Ienzo and Even preferred the theoretical. Elaeus took an uneasy middle ground, partaking in both with the occasional side project in practical biology with Ienzo. Because of this, Braig always sought to include Elaeus in any votes involving classwork. Three against two would win the day, and Ansem would sigh indulgently at his madcap apprentices. _My five vices_, he would call them, until Xehanort arrived and made it one too many.

Braig didn't offer any words when Dilan pushed past. He did not extend kind support, sticky-mouthed sympathies. Instead, the gunner simply worked on his own projects and skipped class in the bargain, sitting patiently in the room and letting Dilan use the bed.

Despite the temperatures, Dilan crawled under the covers and lay there, unable to sleep. The blankets were smothering, oppressive; it was hard to breathe through the heat. He could feel the sweat trickle out of his pores, a fine layer of grime that felt like a second skin between himself and his clothes, an armor of filth that separated him from the world.

Braig's room smelled like oils. Dilan breathed them for a week, refusing to leave the other student's quarters. Neither of them spoke for three of those days; on the fourth, when Braig suddenly asked if he'd seen the masking tape, Dilan answered automatically.

He'd been surprised at the sound of his own voice: rough, husky, but alive.

When he went back to class, no one met his eyes. Even was - for once - tactfully muted, toning down his customary jabs and complaints. Ienzo kept casting nervous glances somewhere in the direction of Dilan's foot. Elaeus scribed patient notes off the chalkboards.

Only Xehanort spoke up, blurting out a raw, awkward question during study hour: "Why didn't anyone use magic to fix her?"

"_Because_, Xehanort," Dilan snapped back, "that kind of power doesn't work correctly. Ienzo's got an entire stack of reference material if you want to read up. When someone dies, their heart goes away. That's it."

"But it could have been recovered. Didn't anyone _try_?"

He'd almost hit Xehanort then - but Dilan had taken a deep breath, and that gave him the time to see the helpless, blank confusion on the other student's face. Xehanort really didn't understand the significance of what he'd asked. It had been the first death of anyone in the castle since the boy's arrival; the issue had never come up before.

"Listen." Dilan's voice felt like lead in his throat. "Accidents happen so that we can prevent them in the future, not so we can undo them."

Xehanort's jaw firmed into a taut line. "I'll argue against you," he said, a soft, strange threat. "Just watch."

And he did, all that week in class: separating compounds that were meant to be permanently fixed, unhooking fused spells that had mingled together so neatly that they fed off hybrid elements. Ansem was full of praise. Xehanort did not relent. Each time he succeeded in another impossible transformation, he stared directly at Dilan. Each time, he delivered the verdict of _reversible_.

Finally, after the fifth day, Dilan lost his temper and hauled Xehanort out to the fountain fields, where he proceeded to hang the boy upside-down by his ankles over the Rising Falls. Braig, following behind, had something about not _killing_ the poor sot, had said it over and over until Dilan calmed down and dropped the student back on solid ground.

Xehanort had flopped onto the lawns, panting. His gasps sounded thin and reedy. Dilan had used the winds to support his weight, and the rush had blown into both their faces, filling their lungs past any need to inhale. He was accustomed to the sensation; Xehanort was not.

Dilan had been wary of what might come next, wary enough that he had loomed over the other student with his fists clenched until Xehanort looked up with that same stunned expression as he'd worn the classroom, and Dilan finally realized: Xehanort didn't follow the same rules as everyone else because he went _beyond_ them. Xehanort saw further. He looked past even the invisible forces that Dilan had lived with all his life - existing in a world that the lancer had not yet begun to imagine was real.

"Listen," Braig started, squatting down next to the younger boy. "Sometimes things need to end, Xehanort. Otherwise nothing new will grow."

The winds calmed, easing away as Dilan loosed his control. Xehanort made a sudden, tiny shake of his head, a spasm of motion that shed grass like pollen-fluff. "I don't like that idea," he confessed. "Why can't things last forever?"

"It's because we're his only family, Dilan," Braig consoled later. The two of them had retired to a hallway near the castle kitchens; Dilan hated looking outside, hated the entire east half of the Castle now. "He can't remember anyone else, so we're all he has. Y'think he's not worried about losing everything all over again, even us?"

* * *

Memory haunts Xaldin, even though he knows it shouldn't.

He wonders sometimes if the weight of their histories is a tangible mass, a counterweight that holds their current identities in check. Their souls are irrevocably linked to their pasts, no matter how far they might travel away from their hearts; memory is what keeps them rooted. Memory of what they had been, of what they had felt, so that they are now defined by loss alone.

That's how the Organization knows what they are: by what they are not.

But there are similarities. So many small, paradoxical comparisons that Xaldin could go mad trying to keep track of them all. Xigbar is more callous since losing his heart - but _Braig_ had always been harsh underneath, if you knew how to watch for it. Zexion is still intense. Vexen worries and complains and tinkers just as much as ever. They have no hearts, but the memories are just as heavy.

Xehanort was never as confident as Xemnas, not when he'd been in control of his senses. Not until the Darkness; and now, Xaldin supposes, the Nothing. The two of them had ended up the exact same way in the end, both of them simmering with their own forms of power. Xehanort, swallowing the Darkness. Xemnas, exhaling Nothing.

Xaldin coaxes his lances out again, and they respond, rotating around an invisible counterweight as the man twists air to obedience. They follow the principles of force manipulation that he learned from his mother: they follow what he remembers, what first taught him control.

The fight winds down to a draw eventually, wild energy bleeding off into the air like so many sparks. Xemnas, laughing, sprawls on the ground, hands planted behind him as he leans back with his chin tilted towards the sky. The twin swords are scattered off to the left; Xaldin knows better than to assume the fight is over, because he's seen how quickly Xemnas can summon them back. His own weapons bob in the air, six wary points angled in the other man's direction. Even though Xaldin's blades are only inches from Xemnas's face, the lancer knows their match is at a stand-off.

Instead, Xaldin makes an impatient gesture towards one of his Dragoons. It swoops forward, just in time to catch the pair of goggles as Xaldin peels them off and tosses them aside. "Have I satisfied your need for a discussion yet, Superior?"

The title is a potential insult, but Xemnas overlooks it with the same ease of long-term sibling rivalry. "Your glasses." A nod to the Dragoon attendant. "Why did you keep them?"

"I didn't." Sweat is trickling between Xaldin's shoulderblades. He mentally curses not taking his jacket off before the spar; too late now, but nothing that a shower can't fix. "They didn't come with me during the transition to becoming a Nobody. But they were useful, so I asked the Dusks to find me another pair."

A scuff, and then Xemnas is drawing his feet closer to his body, turning his slouch into a bunching of muscles that warns of attacks yet to come. "Surely you don't have to waste your time on _machinery_ anymore."

Xaldin isn't a castle engineer; he never has been one despite all his history, and the idea curves his lips in a hard smile. "My mother taught me the virtues of doing things yourself."

"Your mother," Xemnas repeats, thoughtfully. He ignores the weapons hovering dutifully nearby, the way that Xaldin is tensed and ready to parry. Then, "Do you still think of her as that?"

"That depends." Xaldin doesn't move. "Do you still think of us as your friends?"

"Fair point," Xemnas murmurs. He leans forward until the tip of the nearest lance is brushing against his throat. The blade caresses his adam's apple and slides underneath his jaw; Xemnas tilts his head up in that same, guileless expression, the one that makes Xaldin wonder just how little has changed, when Xemnas can look at the world with Xehanort's eyes. "You win."


End file.
